Yes, that's true.

Well, in the first few lessons they introduced the word child, which was orignally pronounced ah-eee (아이). Since 한굴 doesn't connect syllables, this would be pronounced yeo-jaa-ee not yeo-jah-ai. If they did connect syllables, this sentence would be pronounced yee-oh-jah-ai. But instead, we pronounce it sort of like yo-ja-ee. Obviously, 'yo-ja-ee' isn't the perfect pronunciation because romanitizations don't match the letters of 한굴, but it's probably the closest you could get if you used romanitizations (which I don't recommend). Correct me if I am wrong, but this is just from what I have heard.

Its computer thats why

I assume a long vowel is formed

I think 여자 is more like female. Since 아이 means child, 여자아이 would literally be translated as female child i.e girl as young female.

Also, 여자 = female

친구 = friend

여자 친구 = girlfriend

여자 means woman 여자아이 means girl like a little kid since 여자 is woman and 아이 is child 여자친구 is girlfriend because 여자 is woman and 친구 is friend

여자 means woman... So since a "girlfriend" is usually an adult, it's translates to 여자진구 or woman friend... 여자아이 literally means Woman Child... Or girl... Just like 남자아이 directly translates to Man Child...

girl = female child This is the original meaning of the word "girl" No need to add "child" to "girl".

Although some people do use the word "girl" when referring to a young woman and most women enjoy being referred to as younger than they are.

Try putting only 'a girl' and 'a boy'. I always write that and it is always correct.

여자아이 directly translates to Woman Child, just as 남자아이 directly translates to Man Child...